1. Field of the Invention
The present teaching relates to a method for manufacturing a liquid jetting apparatus, and to a liquid jetting apparatus.
2. Description of the Related Art
Japanese Patent Application Laid-open No. 2006-7549 discloses an ink jet head as a liquid jetting apparatus. This ink jet head has a flow passage formation substrate formed with ink flow passages such as a plurality of pressure chambers, and a plurality of piezoelectric elements provided on the flow passage formation substrate to correspond to the plurality of pressure chambers.
The plurality of piezoelectric elements are arranged on an elastic film formed on the flow passage formation substrate to cover the plurality of pressure chambers. Each of the piezoelectric elements includes a piezoelectric film, a lower electrode film arranged on the piezoelectric film on a side near to the flow passage formation substrate, and an upper electrode film arranged on the piezoelectric film on a side far from the flow passage formation substrate. The piezoelectric elements are covered by a moisture-resistant protective film made of aluminum oxide. On the protective film, wires (lead electrodes) are formed to connect to the upper electrode films. Further, the wires are covered by a wire protection film (an insulating film).
The piezoelectric elements and the like each having the above mentioned structure are manufactured through the following steps. First, the lower electrode film of the piezoelectric elements is formed on the elastic film. Next, the piezoelectric film and the upper electrode film are formed and etched to pattern the piezoelectric elements. Next, the protective film is formed and patterned on the upper electrode film. Further, after forming the wires on the protective film to connect with the upper electrode films, the wire protection film is formed and patterned to cover a connecting portion between the wires and the upper electrode films.